1. Field of the Invention
The present invention relates to the field of floating containment booms for restricting the dispersion of petroleum and similar products on the surface of a body of water and for facilitating the recovery and cleanup thereof.
2. Prior Art
The frequency of accidental petroleum spills both at sea as well as in harbors, rivers and the like and the detrimental and long-lasting effects thereof have been subject to ever increasing publicity. This, together with the potential for civil as well as possibly criminal liability for such spills and loss of business because of the adverse publicity, has created increased pressure to both reduce the frequency of such spills and to much better limit the effects of a spill if and when the same does happen.
When a product such as a petroleum product is spilled onto or into a waterway such as by the collision of ships, the running aground of the same, an underwater pipe rupture or the like, the spill will float on the surface of the water in a puddle which will steadily increase in area, and decrease in thickness at least once further spillage is stopped, until the puddle becomes thin enough for the same to breakup into a large plurality of oil covered areas too thin, too large and too numerous for meaningful clean-up from the water. If on the other hand the puddle can be contained before the same grows to an unmanageable size, such as by surrounding the same with an appropriate floating oil boom, the floating oil may be contained from further spreading and removed from the water's surface in a reasonably efficient manner, grossly minimizing the effects of the spill. The key however is in being able to reach the spill site with a sufficient length of oil boom early enough to contain the spill before the same spreads, as may be accelerated by currents, winds, rough water, etc., to cover too large an area to be contained by the oil boom available and in a manner which will allow the efficient recovery of the oil from the surface of the water. For this purpose, it is necessary to deploy an oil boom of sufficient length on site within the first hour or so of a typical spill if the stated objectives are to be achieved.
One of the problems with prior art oil booms is the fact that the same are relatively large for any substantial length thereof, making them expensive, difficult to store and difficult to transport to a spill site and deploy. These factors also usually mean that the length of oil boom available at a typical spill site is usually relatively limited, and for a substantial spill that is at all remotely located, typically the boom is available at the spill site way too late to confine the already relatively well spread-out spill. Thus there is a need for a substantial improvement in the storability of oil booms, the rate at which the same may be delivered on site to a spill and the amount of oil boom which may be quickly and efficiently deployed using both available boats and other equipment.
Attempts have been made in the past to overcome these difficulties with typical prior art oil booms by somehow storing the same in a more compact state, returning the same to the usable state upon deployment. By way of example, U.S. Pat. No. 4,123,911 discloses an oil control system wherein the boom has a longitudinally disposed first chamber for inflation with air and a parallel longitudinally disposed second chamber for inflation with water. The boom itself is stored in a folded, deflated state so that the boom must be inflated from the opposite end thereof. Accordingly, one end of the boom is fastened to apparatus on the ship for inflating the two chambers as more and more of the boom is played out in a very shallow U-shape until the other end of the boom is reached. When deployed in this manner, both ends of the boom are then connected to the same ship, and at that time do not circle the oil spill. Accordingly a second boat must be used to take one end of the boom and drag the same to deploy the boom to its desired position. Obviously the waterfilled chamber of the boom will strongly resist movement of the same through the water other than perhaps along the length of the boom, so that even after the boom is inflated with air and water as described, it will take a substantial length of time to move the boom through the water to a useful position encircling the spill, so that the advantages of small storage volume and inflation during deployment seem to be offset by the difficulties and time required to move the inflated boom to a functional position around an oil spill. Also, it would seem that the material for the boom would have to be very strong, and perhaps cable reinforced, as the movement of the inflated boom is of course accomplished by pulling only on one or both ends thereof. Further, apparently constant inflating is contemplated to maintain the barrier inflation even after deployment. Inflatable containment booms have, however, enjoyed substantial commercial success though are still quite expensive.
Also relating to expandable booms is U.S. Pat. No. 4,480,800 disclosing apparatus for reeling floating booms, particularly such as are self-expanding.
U.S. Pat. No. 3,731,491 discloses an oil containment boom comprised of an elongated strip of corrugated metal which in one form is provided with flotation by means of a strip of plastic material adhesively secured to the corrugated metal. In that form of course the oil boom as deployed is in the same form as that stored, though in another form the flotation means is supplemented with the aid of outrigger or stabilizer floats. A similar system is disclosed in U.S. Pat. No. 3,807,617 wherein the floats are installed to the sheet member as the same is being deployed. Thus deployment requires an operator of the boat as well as an assembler for putting the floats on the sheet material as the same is being played out from a reel, the latter it would appear limiting the allowable speed of deployment and creating the possibility of personal injury to the assembler because of the individual's lack of control over the varying tension and side forces in the sheet material being played out from the rolling and pitching of the boat. As shall subsequently be seen, the present invention eliminates the need for an assembler, essentially allowing the oil boom to be automatically fabricated into its useful state as part of the deployment process and to remain in its useful state without constant inflation.